JP7072977B2 - How to relocate the device - Google Patents

Description

The present invention relates to a device transfer method for transferring a plurality of devices from a wafer to a mounting substrate.

By dividing a wafer in which a plurality of devices are formed along a planned division line (street), a plurality of device chips including the devices can be obtained. This wafer division is carried out using, for example, a cutting device, a laser processing device, or the like.

In the method using a laser processing device, the wafer is evaporated by irradiating the wafer with a laser beam having a wavelength having absorbency along the planned division line, and the wafer is divided. Patent Document 1 discloses a method of irradiating a planned division line of a wafer with a laser beam of pulse oscillation to form a groove and dividing the wafer along the groove. Then, a desired package substrate is manufactured by mounting the device chip obtained by dividing the wafer on the mounting substrate.

Examples of devices formed on wafers include optical devices such as LEDs (Light Emitting Diodes). For example, an optical device can be formed by epitaxially growing an n-type semiconductor layer and a p-type semiconductor layer constituting a pn junction on a substrate made of sapphire or SiC.

Further, in order to transfer the optical device from the wafer to the mounting substrate, a method of separating the optical device from the wafer without dividing the wafer is known. In Patent Document 2, a semiconductor film constituting an optical device is formed on the front surface of a wafer, and then a laser beam is irradiated from the back surface side of the wafer to form a alteration layer near the interface between the wafer and the semiconductor film. A method for separating a wafer and a semiconductor film by a layer is disclosed.

Japanese Unexamined Patent Publication No. 10-305420 Japanese Unexamined Patent Publication No. 2004-72052

As described above, when mounting a device on a mounting board, it is necessary to transfer the device formed on the wafer to the mounting board. The transfer of the device is performed, for example, by picking up the devices one by one from the wafer, transferring them to the mounting board, and repeating the work of die-bonding the devices to a predetermined position on the mounting board. In this case, in order to mount all the devices on the mounting board, a long-time relocation work is required, which reduces productivity.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a device transfer method capable of efficiently transferring a device from a wafer to a mounting substrate.

According to the present invention, there is a device transfer method for transferring a plurality of devices to a mounting substrate provided with a plurality of electrodes, and the plurality of devices formed on the surface side of the substrate via a buffer layer have expandability. After performing the tape sticking step of sticking the tape and the tape sticking step, a laser beam having a wavelength that is transparent to the substrate and absorbable to the buffer layer from the back surface side of the substrate. After performing the buffer layer destruction step of irradiating the buffer layer with the buffer layer to destroy the buffer layer and the buffer layer destruction step, the tape is moved away from the substrate to the substrate and the plurality of devices. By separating the above, a transfer step of transferring the plurality of devices formed on the substrate to the tape, and a plurality of arrangements of the plurality of devices attached to the tape after performing the transfer step are performed. A tape expansion step for expanding the tape and a plurality of the devices attached to the expanded tape after performing the tape expansion step are collectively applied to the plurality of electrodes so as to correspond to the arrangement of the electrodes. A die bonding step for bonding and a method for relocating the device including are provided.

In the present invention, the device may be an LED. The present invention may further include a step of exposing the surface of the device in contact with the tape before or after performing the tape expansion step. Further, in the present invention, the tape contains a pressure-sensitive adhesive made of an ultraviolet curable resin, and further includes a step of irradiating the tape with ultraviolet rays to cure the pressure-sensitive adhesive after performing the tape expansion step. May be good. Further, in the die bonding step, a plurality of the devices are peeled off from the tape by using a transfer unit having a plurality of suction pads arranged so as to correspond to the arrangement of the plurality of devices attached to the tape. It may be connected to a plurality of the electrodes. Further, in the die bonding step, the surface of the tape on which the device is provided and the surface of the mounting substrate on which the electrodes are provided are opposed to each other, and the tape is pressed toward the mounting substrate by a roller. A plurality of the devices may be connected to the plurality of electrodes.

In the device transfer method according to the present invention, first, a plurality of devices formed on a wafer are transferred to an expandable tape. Then, by expanding the expandable tape, the arrangement of the plurality of devices is made to correspond to the arrangement of the mounting positions of the devices on the mounting board, and then the plurality of devices are collectively transferred to the mounting board. This makes it possible to efficiently transfer the device from the wafer to the mounting board.

It is a perspective view which shows the structural example of a wafer. It is sectional drawing which shows the structural example of an optical device wafer. It is a flowchart which shows the example of the device relocation method. It is a perspective view which shows how the optical device wafer is attached to the tape. It is a perspective view which shows typically the state which the optical device wafer is supported by a laser processing apparatus. It is sectional drawing which shows the state that the laser beam is irradiated to the buffer layer. FIG. 7A is a plan view showing how the tape is expanded, and FIG. 7B is a plan view showing the expanded tape. It is a perspective view which shows how a plurality of optical devices are held by a relocation unit. It is a perspective view which shows how a plurality of optical devices are arranged on a mounting board by a relocation unit. It is a perspective view which shows the mounting board in which a plurality of optical devices are bonded. It is a perspective view which shows the state of mounting a plurality of optical devices on a mounting board using a roller.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view showing a configuration example of the wafer 11 according to the present embodiment.

The wafer 11 includes a disk-shaped substrate 13 having a front surface 13a and a back surface 13b. The substrate 13 is divided into a plurality of regions by a plurality of planned division lines (streets) 15 arranged in a grid pattern, and ICs (Integrated Circuits), LEDs, etc. are configured on the surface 13a side of the plurality of regions, respectively. Device 17 is formed.

There are no restrictions on the material, shape, structure, size, etc. of the substrate 13. For example, as the substrate 13, a semiconductor substrate (silicon substrate, SiC substrate, GaAs substrate, InP substrate, GaN substrate, etc.), a sapphire substrate, a ceramics substrate, a resin substrate, a metal substrate, or the like can be used. Further, there are no restrictions on the type, quantity, shape, structure, size, arrangement, etc. of the device 17.

FIG. 2 shows an example of a more specific configuration of the wafer 11. FIG. 2 is a cross-sectional view showing a configuration example of an optical device wafer 19 in which an optical device 25 is formed on a substrate 21 via a buffer layer 23.

A plurality of optical devices 25 are formed on the substrate 21 via a plurality of buffers 23. Each of the optical devices 25 includes a p-type semiconductor layer 27 composed of a p-type semiconductor having a large number of holes and an n-type semiconductor layer 29 composed of an n-type semiconductor having a large number of electrons. A pn junction is formed by the p-type semiconductor layer 27 and the n-type semiconductor layer 29, and an optical device 25 capable of emitting light by recombination of holes and electrons can be obtained.

The buffer layer 23 is composed of, for example, a layer having a function of suppressing the occurrence of defects due to lattice mismatch between the substrate 21 and the p-type semiconductor layer 27, and the material thereof is the lattice constant of the substrate 21 and the p-type semiconductor. It is appropriately selected according to the lattice constant of the layer 27. Further, the buffer layer 23 is a layer that is destroyed by irradiation of a laser beam in the buffer layer destruction step described later, and also functions as a separation layer for separating the substrate 21 and the optical device 25.

The materials of the buffer layer 23, the p-type semiconductor layer 27, and the n-type semiconductor layer 29 are not limited, and can be freely selected as long as the optical device 25 can be formed on the substrate 21. For example, a sapphire substrate, a SiC substrate, or the like is used as the substrate 21, and a buffer layer 23 made of GaN, a p-type semiconductor layer 27 made of p-type GaN, and an n-type semiconductor layer 29 made of n-type GaN are sequentially grown on the substrate 21 by epitaxial growth. Can be formed. For the film formation of each layer, for example, a MOCVD (Metal Organic Chemical Vapor Deposition) method or an MBE (Molecular Beam Epitaxy) method can be used.

Although FIG. 2 shows an optical device 25 composed of a p-type semiconductor layer 27 and an n-type semiconductor layer 29, the configuration of the optical device 25 is not limited to this. For example, an optical device 25 having a light emitting layer between the p-type semiconductor layer 27 and the n-type semiconductor layer 29 and emitting light from the light emitting layer can also be used.

When a package substrate is manufactured using the device 17 represented by the optical device 25 (see FIG. 1), it is necessary to transfer the device 17 from the wafer 11 to the mounting substrate. This relocation can be carried out, for example, by picking up the devices 17 formed on the substrate 13 one by one and die-bonding them to predetermined positions on the mounting board, but this method consumes a huge amount of work time for the relocation of the devices 17. ..

In the device transfer method according to the present embodiment, first, a plurality of devices 17 formed on the substrate 13 are transferred to a tape (tape having expandability) whose shape can be expanded by an external force. Then, by expanding the expandable tape, the arrangement of the plurality of devices 17 corresponds to the arrangement of the mounting positions of the devices on the mounting board, and then the plurality of devices 17 are collectively transferred to the mounting board. This makes it possible to efficiently transfer the device 17 from the wafer 11 to the mounting substrate.

FIG. 3 is a flowchart showing an example of a device relocation method according to the present embodiment. Hereinafter, a method of relocating the device according to the present embodiment will be described with reference to FIG. In the following, as an example, a case where the optical device 25 is separated from the optical device wafer 19 (see FIG. 2) and transferred to the mounting substrate will be described.

First, the tape sticking step S1 for sticking the expandable tape to the plurality of optical devices 25 formed on the substrate 21 is carried out. FIG. 4 is a perspective view showing how the optical device wafer 19 is attached to the tape 31. A plurality of optical devices 25 (not shown) are formed on the surface 21a side of the disk-shaped substrate 21. Further, the tape 31 is a tape (tape having expandability) that can be expanded (stretched) by an external force.

An annular frame 33 is attached to the outer peripheral portion of the tape 31, and a plurality of optical devices 25 formed on the surface 21a side of the substrate 21 are attached to the tape 31. As a result, the optical device wafer 19 is supported by the frame 33 with the back surface 21b side of the substrate 21 exposed upward.

The material of the tape 31 has expandability, and there is no limitation as long as a plurality of optical devices 25 can be adhered to each other. However, since the plurality of optical devices 25 can be easily separated from the tape 31 in a later step, the adhesive of the tape 31 is made of a material having a property that the adhesive strength is lowered by an external stimulus such as light or heat. Is preferable. For example, an ultraviolet curable resin can be used as the pressure-sensitive adhesive for the tape 31.

Next, the buffer layer destruction step S2 is performed in which the buffer layer 23 is irradiated with a laser beam from the back surface 21b side of the substrate 21 to destroy the buffer layer 23. In the buffer layer destruction step S2, first, the optical device wafer 19 is supported by a laser processing device.

FIG. 5 is a perspective view schematically showing a state in which the optical device wafer 19 is supported by the laser processing device 2. The laser processing apparatus 2 uses a chuck table 4 for holding the optical device wafer 19 and a laser beam having a wavelength that is transparent to the substrate 21 of the optical device wafer 19 and is absorbent to the buffer layer 23. It is provided with a laser processing unit 6 capable of irradiating.

The chuck table 4 sucks and holds the optical device wafer 19 via the tape 31. Specifically, the upper surface of the chuck table 4 is a holding surface for holding the optical device wafer 19, and this holding surface is a suction source (not shown) through a suction path (not shown) formed inside the chuck table 4. ) Is connected.

The frame 33 is fixed by a clamp 14 (see FIG. 6) provided in the laser processing apparatus 2, and the negative pressure of the suction source is applied to the holding surface while the optical device wafer 19 is supported by the holding surface of the chuck table 4. Then, the optical device wafer 19 is sucked and held by the chuck table 4. Further, the chuck table 4 is moved in the machining feed direction (X-axis direction) and the index feed direction (Y-axis direction) by a movement mechanism (not shown).

The optical device wafer 19 is sucked and held by the chuck table 4 so that the back surface 21b of the substrate 21 is exposed upward. In this state, the laser beam is irradiated from the laser processing unit 6 toward the optical device wafer 19.

The laser processing unit 6 has a cylindrical casing 8. At the tip of the casing 8, a condenser for condensing a pulsed laser beam oscillated from a pulsed laser beam oscillator (not shown) such as a YAG laser oscillator or a YVO ₄ laser oscillator provided in the laser processing apparatus 2. 10 is attached.

Further, the casing 8 is equipped with an image pickup means 12 for imaging an irradiation region of a laser beam. The image acquired by the image pickup means 12 is used for image processing such as pattern matching for aligning the condenser 10 and the optical device wafer 19. As a result, the irradiation position of the laser beam can be adjusted.

When irradiating the buffer layer 23 formed on the surface 21a side of the substrate 21 with a laser beam, the chuck table 4 is moved under the condenser 10, has transparency to the substrate 21, and is a buffer layer. A laser beam having a wavelength that is absorbent to 23 is focused by the condenser 10 and irradiated to the buffer layer 23. The intensity of the laser beam is set so that the buffer layer 23 can be destroyed.

FIG. 6 is a cross-sectional view showing how the buffer layer 23 is irradiated with a laser beam. A plurality of optical devices 25 formed on the surface 21a side of the substrate 21 are attached to the tape 31. Further, the frame 33 is fixed by the clamp 14, and the optical device wafer 19 is sucked and held by the chuck table 4 so that the back surface 21b side of the substrate 21 is exposed upward.

When the optical device wafer 19 is irradiated with a laser beam, the laser beam passes through the substrate 21 and is absorbed by the buffer layer 23, and the buffer layer 23 is destroyed. It is not necessary to completely separate the substrate 21 and the buffer layer 23 by irradiating the laser beam, and the substrate 21 and the buffer layer 23 can be separated when the tape 31 is peeled from the optical device wafer 19 in a later step. It suffices if the buffer layer 23 is destroyed to some extent.

Next, the transfer step S3 is performed in which the substrate 21 and the optical device 25 are separated and the plurality of optical devices 25 formed on the surface 21a side of the substrate 21 are transferred to the tape 31.

In the transfer step S3, the tape 31 attached to the optical device wafer 19 is peeled off. Specifically, the tape 31 is moved in a direction away from the substrate 21. At this time, the buffer layer 23 provided between the substrate 21 and the optical device 25 is destroyed in the buffer layer destruction step S2, and the bond between the substrate 21 and the optical device 25 is weakened. Therefore, when the tape 31 is moved, the optical device 25 follows the tape 31 and is separated from the substrate 21.

When peeling the tape 31 from the optical device wafer 19, a peeling member such as a blade may be inserted between the substrate 21 and the optical device 25 to promote the separation between the substrate 21 and the optical device 25. As a result, the optical device 25 can be separated from the substrate 21 even if the buffer layer 23 is not sufficiently destroyed in the buffer layer destruction step S2.

Next, a tape expansion step S4 is performed in which the tape 31 on which the plurality of optical devices 25 are transferred is expanded to change the interval between the optical devices 25. FIG. 7A is a plan view showing how the tape 31 to which the plurality of optical devices 25 are attached is expanded.

Since the tape 31 has expandability, it can be expanded by applying an external force. Then, when the tape 31 is expanded, the distance between the adjacent optical devices 25 is widened, and the arrangement of the plurality of optical devices 25 is changed. FIG. 7B is a plan view showing the expanded tape 31. As shown in FIG. 7B, when the tape 31 is expanded, the distance between the optical devices 25 increases according to the expansion amount of the tape 31.

The plurality of optical devices 25 attached to the tape 31 are mounted on the mounting board in a predetermined arrangement in a later step. Therefore, in the tape expansion step S4, the tape 31 is expanded so that the arrangement of the optical device 25 attached to the tape 31 corresponds to the arrangement of the optical device 25 on the mounting board. For example, when a plurality of optical devices 25 attached to the tape 31 are connected to a plurality of electrodes provided on the mounting board in a predetermined arrangement, the arrangement of the optical devices 25 attached to the tape 31 is the arrangement of the plurality of electrodes. The tape 31 is extended to correspond to the arrangement.

The fact that the arrangement of the plurality of optical devices 25 corresponds to the arrangement of the plurality of electrodes means that the plurality of optical devices 25 are arranged at intervals so that they can be connected to desired electrodes. For example, the tape 31 may be expanded so that the distance between the plurality of optical devices 25 attached to the tape 31 is substantially the same as the distance between the plurality of electrodes formed on the mounting substrate.

There is no limitation on the method of expanding the tape 31, and it can be performed by using a dedicated expansion device or the like. For example, an expansion device including a support unit that supports the outer peripheral portion of the tape 31 and a contact portion that abuts on the back surface (the surface on which the optical device 25 is not formed) side of the tape 31 can be used. In this case, with the outer peripheral portion of the tape 31 supported by the support unit, the central portion on the back surface side of the tape 31 is brought into contact with the abutting portion, and the abutting portion is relative to the front surface side from the back surface side of the tape 31. The tape 31 can be expanded by moving it to.

Note that FIGS. 7A and 7B show how the tape 31 is expanded with the frame 33 (see FIG. 4 and the like) removed from the tape 31, but the expansion of the tape 31 is the frame 33. May be carried out with the attached. For example, the tape 31 can be expanded while the frame 33 attached to the tape 31 is supported by the support unit of the expansion device.

After the tape expansion step S4, it is preferable to perform a process of reducing the adhesive strength of the tape 31 so that the optical device 25 can be easily peeled off from the tape 31 in a later step. For example, when the adhesive of the tape 31 is an ultraviolet curable resin, the tape 31 can be cured and the adhesive strength of the tape 31 can be reduced by performing the step of irradiating the tape 31 with ultraviolet rays.

Next, a die bonding step S5 is performed in which the plurality of optical devices 25 attached to the expanded tape 31 are collectively transferred to the mounting substrate and bonded. In the die bonding step S5, the plurality of optical devices 25 attached to the tape 31 are transferred to the mounting substrate and mounted while maintaining the arrangement of the plurality of optical devices 25. Therefore, it is not necessary to align the plurality of optical devices 25 with the mounting board for each optical device 25, and the devices can be efficiently transferred from the tape 31 to the mounting board.

The method of transferring the plurality of optical devices 25 to the mounting board is not particularly limited. For example, a relocation unit may be used in which a plurality of optical devices 25 are collectively picked up from the tape 31 and transferred to the mounting board, or a plurality of optical devices 25 can be mounted on the mounting board by directly attaching the tape 31 to the mounting board. It may be transferred.

A method of transferring the plurality of optical devices 25 to the mounting board by the transfer unit will be described with reference to FIGS. 8 and 9. FIG. 8 is a perspective view showing how the plurality of optical devices 25 are held by the transfer unit 20. The relocation unit 20 includes a plate-shaped base 22 and a plurality of suction pads 24 provided on the lower surface side of the base 22 to suck and hold the optical device 25.

First, the tape 31 is held horizontally so that the plurality of optical devices 25 are exposed upward, and the transfer unit 20 is arranged above the tape 31. Then, the relocation unit 20 is moved downward in the vertical direction, and the plurality of suction pads 24 are brought into contact with the optical device 25, respectively. In this state, the plurality of optical devices 25 are held by the relocation unit 20 by sucking the plurality of optical devices 25 with the plurality of suction pads 24. After that, by moving the transfer unit 20 upward in the vertical direction while holding the tape 31 in place, the plurality of optical devices 25 are separated from the tape 31 and picked up by the transfer unit 20. As a result, the surface of the optical device 25 in contact with the tape 31 is exposed.

The plurality of suction pads 24 are arranged so as to correspond to the arrangement of the plurality of optical devices 25 attached to the tape 31. Specifically, the distance between the plurality of suction pads 24 substantially coincides with the distance between the plurality of optical devices 25 attached to the tape 31. Therefore, by using the relocation unit 20, it is possible to pick up a plurality of optical devices 25 at once.

After that, the transfer unit 20 is moved onto the mounting board to which the plurality of optical devices 25 are transferred. FIG. 9 is a perspective view showing how a plurality of optical devices 25 are arranged on the mounting board 35 by the relocation unit 20. A plurality of electrodes connected to the optical device 25 are formed on the mounting substrate 35, respectively. Here, as an example, the optical device 25 is a red LED, and the mounting substrate 35 has a plurality of electrodes 37R connected to the red LED, a plurality of electrodes 37G connected to the green LED, and a plurality of electrodes 37B connected to the blue LED. Is shown as an example of the formation of.

First, the mounting substrate 35 is placed at a predetermined position, and an adhesive such as silver paste is applied onto the plurality of electrodes 37R. Then, the relocation unit 20 is positioned so that the suction pads 24 are arranged above the plurality of electrodes 37R. After that, the relocation unit 20 is moved downward in the vertical direction, and the surfaces of the plurality of optical devices 25 in contact with the tapes 31 are connected to the electrodes 37R via adhesives. In this way, the plurality of optical devices 25 are bonded to the mounting substrate 35.

The plurality of suction pads 24 are provided so that their arrangement corresponds to the arrangement of the plurality of electrodes 37R. Therefore, by using the relocation unit 20, a plurality of optical devices 25 can be collectively bonded to the mounting substrate 35.

FIG. 10 is a perspective view showing a mounting board 35 to which a plurality of optical devices 25 are bonded. An optical device 25 composed of a red LED is bonded to each of a plurality of electrodes 37R (see FIG. 9) provided on the mounting substrate 35. Then, by carrying out the step of collectively bonding the green LED to each of the plurality of electrodes 37G and the step of collectively bonding the blue LED to each of the plurality of electrodes 37B by the same method, the three-color LED is mounted. LED packages can be manufactured.

When the optical device 25 is relocated using the relocation unit 20, the surface side (back surface side) of the optical device 25 in contact with the tape 31 is connected to the electrode formed on the mounting substrate, but the optical device 25 is connected. The surface side (surface side) that does not come into contact with the tape 31 can also be connected to the electrode. FIG. 11 shows an example of a method of connecting the surface side of the optical device 25 to an electrode formed on the mounting substrate 25.

FIG. 11 is a perspective view showing how a plurality of optical devices 25 are mounted on the mounting board 35 using the rollers 26. When mounting a plurality of optical devices 25 on the mounting board 35 using the rollers 26, first, the mounting board 35 is placed at a predetermined position, and an adhesive such as silver paste is applied to the electrodes formed on the mounting board 35. Then, the surface 31a (the surface on which the plurality of optical devices 25 are formed) of the expanded tape 31 and the surface on which the electrodes of the mounting substrate 35 are formed face each other. At this time, the tape 31 and the mounting substrate 35 are positioned so that the plurality of optical devices 25 are arranged on the plurality of electrodes (electrode 37R in FIG. 11), respectively.

After that, the roller 26 is rotated in the direction indicated by the arrow A, and the roller 26 presses the back surface 31b (the surface on which the optical device 25 is not formed) of the tape 31 toward the mounting substrate 25. As a result, the plurality of optical devices 25 are connected to the electrodes 37R via adhesives and bonded to the mounting substrate.

As the adhesive material for adhering the electrode 37R and the optical device 25, an adhesive having a higher adhesive force than that of the tape 31 is used. By performing the above-mentioned treatment for reducing the adhesive strength of the tape 31 (such as irradiation with ultraviolet rays), the adhesive strength required for the adhesive applied to the electrode 37R is reduced, and the degree of freedom in selecting the adhesive material is increased. Can be done.

After that, by peeling the tape 31 from the mounting board 25, the plurality of optical devices 25 and the tape 31 are separated, and a mounting board 35 to which the plurality of optical devices 25 are bonded is obtained (see FIG. 10).

As described above, in the device relocation method according to the present embodiment, after the plurality of optical devices 25 are attached to the expandable tape 31, the arrangement of the plurality of optical devices 25 is adjusted by expanding the tape 31. The arrangement of the plurality of optical devices 35 attached to the tape 31 can correspond to the arrangement of the mounting positions of the optical devices 25 on the mounting board 35. As a result, a plurality of optical devices 35 can be collectively transferred to the transfer substrate, and the devices can be efficiently transferred.

In particular, when manufacturing an LED package or the like in which a large number of LEDs are arranged on a mounting board at a predetermined cycle, if a plurality of devices formed on the same wafer can be collectively arranged on the mounting board at a predetermined interval, the device can be manufactured. The efficiency of relocation work is greatly improved. Therefore, the device relocation method according to the present embodiment is particularly useful when a plurality of LEDs are relocated to a relocation substrate to produce an LED package.

Further, in the device relocation method according to the present embodiment, the expandable tape 31 is expanded, the distance between the plurality of optical devices 25 is widened, and then the device is picked up. Therefore, it is possible to prevent damage to the optical devices 25 due to contact between the optical devices 25 during pickup, and it is possible to improve the yield.

In the above embodiment, an example is shown in which all the optical devices 25 attached to the tape 31 are collectively transferred to the mounting substrate 25, but all the optical devices 25 are transferred by performing the die bonding step S5 a plurality of times. It may be relocated. That is, all the optical devices 25 may be transferred by repeating the work of transferring a part of the plurality of optical devices 25 attached to the tape 31 to the mounting board 35 a plurality of times.

When the die bonding step S5 is performed a plurality of times, the tape expansion step S4 may be performed again after the die bonding step S5 is performed. That is, after partially transferring a part of the plurality of optical devices 25 attached to the tape 31 to the mounting board 35, the tape 31 is expanded and the arrangement of the remaining optical devices 25 is adjusted again, and then the next transfer operation is performed. May be done.

In particular, when it is difficult to arrange all the optical devices 25 at a desired position by expanding the tape 31 once due to the influence of the variation in the expansion amount of the tape 31, the optical device 25 is relocated as described above. It is preferable to perform this in a plurality of times and perform the tape expansion step S4 each time to adjust the arrangement of the optical device 25. As a result, the spacing between the optical devices 25 can be controlled with high accuracy, and the mounting substrate 35 can be easily arranged at a desired position.

Further, when the optical device 25 is bonded to the mounting substrate 35, the bonding surface of the optical device 25 can be appropriately changed. Specifically, either the surface side (back surface side) of the optical device 25 shown in FIG. 7B in contact with the tape 31 or the surface side (front surface side) not in contact with the tape 31 may be adhered to the mounting substrate 35. .. When changing the adhesive surface of the optical device 25, a step of replacing the exposed surface of the optical device 25 is performed before the die bonding step S5.

For example, after the tape expansion step S4, the back surface side of the optical device 25 can be exposed and the back surface side of the optical device 25 can be adhered to the mounting substrate by using the methods shown in FIGS. 8 and 9. In FIG. 9, the front surface side of the optical device 25 is adsorbed by the suction pad 24, and the back surface side is exposed.

Further, the back surface side of the optical device 25 may be exposed by re-covering the tape before the tape expansion step S4. Specifically, before the tape 31 to which the plurality of optical devices 25 are attached is expanded (see FIG. 7A), the tape for replacement is attached to the surface side of the plurality of optical devices 25. After that, the tape 31 is peeled off to separate the plurality of optical devices 25 and the tape 31, so that the plurality of optical devices 25 are transferred to the reattachment tape with the back surface side exposed.

In this case, in the subsequent tape expansion step S4, since the replacement tape is expanded to change the arrangement of the optical device 25, a replacement tape having expandability is used. Further, when a reattachment tape is used, the tape 31 does not necessarily have to have expandability.

Further, although the case where the optical device 25 formed mainly via the buffer layer 23 is relocated on the substrate 21 has been described above, the type of the device to be relocated is limited by the device relocation method according to the present embodiment. not. Further, the material of the buffer layer 23 can also be appropriately selected if it can be destroyed by irradiation with a laser beam in the buffer layer destruction step S2.

In addition, the structure, method, and the like according to the above-described embodiment can be appropriately modified and implemented as long as they do not deviate from the scope of the object of the present invention.

11 Wafer 13 Substrate 13a Front surface 13b Back surface 15 Scheduled division line 17 Device 19 Optical device wafer 21 Substrate 21a Front surface 21b Back surface 23 Buffer layer 25 Optical device 27 p-type semiconductor layer 29 n-type semiconductor layer 31 Tape 31a Front surface 31b Back surface 33 Frame 35 mounting Substrate 37R Electrode 37G Electrode 37B Electrode 2 Laser processing device 4 Chuck table 6 Laser processing unit 8 Casing 10 Condenser 12 Imaging means 14 Clamp 20 Relocation unit 22 Base 24 Adsorption pad 26 Roller

Claims (6)

It is a device transfer method for transferring a plurality of devices to a mounting board having a plurality of electrodes.
A tape sticking step for sticking an expandable tape to a plurality of the devices formed on the surface side of the substrate via a buffer layer, and a tape sticking step.
After performing the tape application step, the buffer layer is irradiated with a laser beam having a wavelength that is transparent to the substrate and absorbable to the buffer layer from the back surface side of the substrate. The buffer layer destruction step that destroys the buffer layer, and
After performing the buffer layer destruction step, the tape is moved away from the substrate to separate the substrate from the plurality of devices, whereby the plurality of the devices formed on the substrate are attached to the tape. And the transfer step to transfer to
After performing the transfer step, a tape expansion step that expands the tape so that the arrangement of the plurality of devices attached to the tape corresponds to the arrangement of the plurality of electrodes.
A method for relocating a device, which comprises performing the tape expansion step and then collectively bonding a plurality of the devices attached to the expanded tape to the plurality of electrodes. The method for relocating a device according to claim 1, wherein the device is an LED. The method for relocating a device according to claim 1, further comprising a step of exposing the surface of the device in contact with the tape before or after performing the tape expansion step. The tape contains a pressure-sensitive adhesive made of a UV curable resin.
The method for relocating a device according to claim 1, further comprising a step of irradiating the tape with ultraviolet rays to cure the pressure-sensitive adhesive after performing the tape expansion step. In the die bonding step, a plurality of the devices are peeled off from the tape by using a transfer unit having a plurality of suction pads arranged so as to correspond to the arrangement of the plurality of devices attached to the tape. The method for relocating a device according to claim 1, wherein the device is connected to the electrode. In the die bonding step, a plurality of surfaces of the tape on which the device is provided and a surface of the mounting substrate on which the electrodes are provided are opposed to each other, and the tape is pressed toward the mounting substrate by a roller. The method for relocating a device according to claim 1, wherein the device is connected to a plurality of the electrodes.

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